Infants might not commit too many sins, but have inherited generational curses, which are judgements that are passed on to individuals because of sins perpetuated in a family in a number of generations. Generational curses are similar to original sin curses because they can be passed down on a generational basis. They differ in that generational curses do not impose eternal judgement. They bring judgement or bondage during an individual's life, reducing the quality of life, until that individual addresses the sin issues that put the curses into place.This is similar in spirit to the beliefs of Buddhists (Tibetan or otherwise) who believe that if someone is born (reincarnation) into a lower caste, they deserve it because of some indiscretion in a previous life. Conversely if someone is born into a higher caste, they deserve it because they were wronged or were good in a previous life.
On the surface it appears to be a rather benign belief however behind these unprovable dogmas lies injustice and inequality. To compound the misery of being born into the lower class, one is subjected to extra punishment because they obviously deserve it...Thus gives slave masters the rite to beat their slaves should they try to escape or rebel.
One can see why these beliefs became influential - like many unfounded religious beliefs, they are good for the control of the populace and keeping the status quo in favour of those born with a silver spoon in their mouth.
“Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful.” - SenecaPerhaps most disappointing, this isn't something that was left in the past but was present in Tibet circa 1950. This is what bothers me about the "Free Tibet" movement. Do they understand that it was actually really bad for the lower class before China "liberated" them? (Not that communistic China with religious intolerance is necessarily better) Are they just returning the power to those who never deserved it in the first place, those who believe they ought to be in power through divine rite? One can only hope that the Dalai Lama has used his time in exile to Westernise himself and strive for a progressive Tibet, should China ever allow secession. However I very much doubt China will relinquish Tibet unless a Soviet style collapse occured - in other words, very unlikely.
As a final note I don't find it surprising that those who hold onto these beliefs and vigorously defend them are the ones who were born on the right side of the ledger. Golden rule be damned!